Try keeping everything the same and double the power!!! Go with the 600-700 watt suggestion before you do anything.

It takes power to go low and increase bass. With only 300 watts per speaker, you're not going to go where you want I don't think...

Just my $0.02

id stick with the 10's and get more amp if the subs can take it:)

Well doubling the power on the 10's is not even going to be noticed .. I'd be lucky to get 3db's . and everything under that level of a change won't make a difference. The 10's can only take 200 rms each . I just don't want to risk adding way more power and then blowing the subs and being sol with no system. But thanks for the help i just figured 1 decent 15 is better than 2 entry level subs.

I had 10" subs once. That lasted 3 days before i took them back, traded for 12's. That was about 1992...
I've had 2 12's of various flavours ever since. Till I got my new car last year and with more room, decided to go for 15's.
Found out what i'd been missing for all those years.....
I'd never go smaller than 15 again. I like my bass low in frequency, not low in volume.

Likewise.

I had the same subs and overpowered them a lot without any failures, they can take a beating. I'd build a ported box and give them more power personally.

Sad thing is though, even with almost 1000 rms to one of them in a ported box it still didn't have much low end extension.

You are correct - a decent 15" in a properly designed Bass Reflex enclosure will *kill* what you currently have. Sound quality is certainly not a strong point of MTX IMO.

Best,
Mark

If I were to upgrade to say a MAW-15 would my current phoenix gold 5.0:1 which runs at 317 RMS at 2 ohms be sufficient or should I upgrade to something that is 600 rms - 700 rms. My budget isn't too much . Just whatever I can sell my current setup for plus maybe 100$CAD.

The sub will cost you $110 total. Use the money you get from selling you're stuff to get a 600-700w mono amp.